CEO of Tesla, Elon Musk is seen delivering speech at the wind and solar battery plant outside of Jamestown, South Australia, on Friday. Photo: MORGAN SETTE

The deadline is an unmissable one for Tesla’s head Elon Musk, who bet the Atlassian’s co-founder Mike Cannon-Brookes over Twitter that his company can build and install the unit power in 100 days, or the $US50 million ($64million) system is free.

The system is part of the state’s wider $550 million plan to power South Australia.

The Tesla batteries can supply power to up to 300,000 homes. Photo: Timothy Artman

Mr Musk used the event to compliment South Australia on its commitment to renewable energy.

This is a great example to the rest of the world of what can be done,» he said.

«When this is done in just a few months, it will be the largest battery installation by a factor of three.»

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The countdown officially started on Friday after Australian Energy Market Organiser and South Australian transmission firm Electranet signed an interconnection agreement to install Tesla’s powerpack battery system.

However, with half the installation already complete, it looks ready to run by December 1.

The 100 megawattt/129 MWh system is designed to reduce intermittency issues and manage increased demand during summer peak loading periods, potentially providing enough energy to power 30,000 homes.

It will be paired with French firm Neoen’s Hornsdale wind farm, located near Jamestown, about 200 kilometres north of Adelaide.

The powerpacks will be manufactured at Tesla’s Gigafactory in Sparks, Nevada, in the US.

Tesla had a closing price of $US341.10 on the Nasdaq following the unveiling.